278 



ball and socket arc wider than high, and arc widest below the middle. The 

 outline of the articular surfaces is emarginatc and sloping at the sides above, 

 and semicircular below. The neural canal is triangular. The transverse pro- 

 cesses project obliquely from the lower part of the body, and they become 

 successively narrower. The hypapophyses are excavated into deep conical 

 pits, directed obliquely backward, for movable articulation with chevrons. 

 The pits are small in the first of the series of specimens and become succes- 

 sively larger. 



Measurements of the two vertebrae represented are as follows : 



Length of centrum, including edge of ball 



Width of ball 



Depth of ball 



Inches. 



Inches. 



1. 65 1. 45 



1.75 1.65 



1. 50 1. 45 



In a consecutive series of four posterior caudals with small diapophyses, 

 the bodies have nearly the same form as in the preceding, but the articular 

 extremities are of more uniform diameter and of a more hexahedral outline. 

 The transverse processes are small and project just below the center of the 

 sides. The chevron-pits are well developed, and resemble those of the pre- 

 ceding caudal specimens. Two of the caudals are represented in Figs. 11, 12, 

 Plate XXXVI. 



The four caudals together measure 5.3 inches in length. The diameters 

 of the cup of the first of the series is 1.4 inches ; the diameters of the ball 

 of the last of the series is 1.3 inches. 



A mutilated posterior caudal centrum, apparently of the same animal as 

 the preceding, is without diapophyses, but has well-produced chevron-pits. 

 The length of the centrum is less than the depth, and this is greater than the 

 width. The articular ends are hexahedral in outline. The centrum 

 measures .9 inch in length ; 1.2 inches wide, and 1.3 inches deep. 



The same collection contains the greater part of a palate-bone, with teeth, 

 represented in Fig. 12, Plate XXXIV, which may perhaps belong to the 

 same species as the specimens above described. The specimen contains the 

 remains of seven teeth, which probably is within two or three of the 

 complete series. The teeth are compressed conical, strongly curved back- 

 ward or hooked, obtuse in front, acute-edged behind, are perfectly smooth, 

 and present no facets or subclivisional planes of the surface. 



